Termites, insects of the order Isoptera, live almost exclusively on cellulose in vegetable matter. However, they can cause considerable damage to other materials in their quest for cellulose, including structural damage to buildings, destruction of foods such as growing crops, grassland, forestry (especially young saplings), household goods, stored food, cellulose based materials such as wood, paper, cotton, fiber matter, and the like. The tendency to attack each of the above materials will vary from species to species.
Damage to structures or other materials may be prevented or diminished by the use of insecticidal compounds active against termites. Such compounds are conventionally applied either to the termite infested material itself or to its component members, e.g., by treatment of timber components before incorporation of the timber into the building, or to soil area surrounding the building.
The majority of commercially available insecticides do not have the combination of biological and physicochemical properties necessary for effective termite control (e.g., activity against termites combined with long-term persistence), although the chlorinated hydrocarbon aldrin has proved effective.
However, increased regulatory controls on chlorinated hydrocarbons have created a need for a termiticide which combines the necessary activity and persistence with a low mammalian toxicity.
Certain acyl urea compounds are claimed to be effective against termites. For instance, U.S. Pat. No. 4,833,158 claims flufenoxuron as a termiticide; and diflubenzuron has also been disclosed specifically as a termiticide.
Hexaflumuron (N-(((3,5-dichloro-4-(1,1,2,2-tetrafluoroethoxy)phenyl)-amino)carbonyl)-2, 6-difluoro benzazmide), a compound with a low mammalian toxicity, has been described as possessing insecticidal activity against insects from the orders Lepidoptera, Coleoptera, Diptera, Orthoptera, Homoptera, Thysanoptera, and Acarina (U.S. Pat. No. 4,468,405). It has now been found that hexaflumuron and other structurally related compounds are surprisingly more effective as a termiticide than structurally unrelated acyl urea compounds such as, for instance, diflubenzuron.